1. Field of the Invention
The invention relates to computer terminals and systems for use in retail establishments for use by customers to locate a product, and in particular, to terminals including a bar code reader.
2. Description of the Related Art
Conventional portable data terminals comprise a data display, data input means such as a keyboard and data storage and processing means. A wide range of applications are now available on such terminals including word-processing, spread-sheeting, data base applications and so forth. Much of the development work in known portable data terminals is centered on increasing the data storage and processing capabilities. This has led to increases in cost and size/weight (and the corresponding need to subsequently miniaturise components) together with increased complexity leading to increased potential for defect or breakdown.
In another aspect, U.S. Pat. No. 5,410,326 relates to a programmable remote control device for interacting with a plurality of remotely controlled devices. The remote control device is configured to control a variety of devices and carries pictorial icons representing the different functions for selection by the user. The device is further configured to receive and display advertising messages, and operate various other functions such as electronic mail and order-out meal delivery. The system is, however, complex and cumbersome and of limited adaptability.
U.S. Pat. No. 5,521,370 relates to a hand-held portable data capture terminal for example for warehousing, which is mountable in a terminal mount for data communication with a host computer and/or battery recharging. The specification is directed to a data interface between the terminal and the terminal mount comprising abutting electrical contact pads. The terminal is arranged only to communicate with the terminal mount when it is docked therein. The terminal carries a processor and memory system serving as a communication controller and can be arranged to act as network controllers when docked. A difficulty with such a system is that a considerable processing and memory capability is included in the hand-held terminal and that data is only downloaded when the terminal is docked in terminal mount.
U.S. Pat. No. 5,280,621 relates to a control system for a personal computer. In conventional personal computers a system control processor provided an interface between the host processor and peripheral such as a keyboard. System performance was limited because of the slow communication rate between the system control processor and the keyboard, and was further degraded when the system control processor handled additional control burdens such as battery power management, external bus expansion control and so forth. According to U.S. Pat. No. 5,280,621 it is proposed to introduce microcontrollers to provide communication between respective peripheral devices and the system control processor, freeing the system control processor to do other tasks improving the overall system performance.
The question of power management in portable devices has been addressed in various manners conventionally. U.S. Pat. No. 5,027,294 relates to monitoring the voltage discharge of a battery power supply in which the user is issued warnings at various depletion levels allowing memory back-up, avoidance of over-depletion and so forth. U.S. Pat. No. 5,504,413 recites a battery charging system including feedback input allowing minimisation of overhead voltage levels, and connection of a recharging device to a peripheral device via a port at the recharger. U.S. Pat. No. 5,487,181 refers to power minimisation providing a main processor and a lower power processor which allows the main processor to “sleep” except when required. The lower power processor carries out various minor functions allowing the main processor to sleep as far as possible whilst being awoken as soon as required. U.S. Pat. No. 5,511,205 relates power management in a portable pen-based notebook computer. The system has a plurality of independently controllable power planes selectively powerable to ensure that a particular task is performed with minimum power consumption. In addition separate CPU's operate synchronously in relation to one another reducing the amount of processing time the main CPU is required to dedicate to the power management function.